Principal Investigator(s):Rosero-Bixby, Luis, Centro Centroamericano de Población (CCP), University of Costa Rica; Fernández, Xinia, Centro Centroamericano de Población (CCP), University of Costa Rica; Dow, William H., University of California-Berkeley

Summary:

The Costa Rican Longevity and Healthy Aging Study (CRELES, or Costa Rica Estudio de Longevidad y Envejecimiento Saludable) is a nationally representative longitudinal survey of health and lifecourse experiences of 2,827 Costa Ricans ages 60 and over in 2005. Baseline household interviews were conducted between November 2004 and September 2006, with two-year follow-up interviews. The sample was drawn from Costa Rican residents in the 2000 population census who were born in 1945 or before, with an over-sample of the oldest-old (ages 95 and over).... (more info)

The Costa Rican Longevity and Healthy Aging Study (CRELES, or Costa Rica Estudio de Longevidad y Envejecimiento Saludable) is a nationally representative longitudinal survey of health and lifecourse experiences of 2,827 Costa Ricans ages 60 and over in 2005. Baseline household interviews were conducted between November 2004 and September 2006, with two-year follow-up interviews. The sample was drawn from Costa Rican residents in the 2000 population census who were born in 1945 or before, with an over-sample of the oldest-old (ages 95 and over). The main study objective was to determine the length and quality of life, and its contributing factors in the elderly of Costa Rica. Vital statistics indicate that Costa Rica has an unusually high life expectancy for a middle-income country, even higher than that of the United States, but CRELES is the first nationally representative survey to investigate adult health levels in Costa Rica. CRELES public use data files contain information on a broad range of topics including self-reported physical health, psychological health, living conditions, health behaviors, health care utilization, social support, and socioeconomic status. Objective health indicators include anthropometrics, observed mobility, and biomarkers from fasting blood and overnight urine collection (such as cholesterol, glycosylated hemoglobin, C-reactive protein, cortisol, and other components of integrative allostatic load measures). Mortality events are tracked and conditions surrounding death are measured in a surviving family interview (longitudinal follow-up data are not yet publicly available).

The study was conducted by the University of Costa Rica's Centro Centroamericano de Población in collaboration with the Instituto de Investigaciones en Salud, with the support of the Wellcome Trust (grant 072406). The Principal Investigator is Luis Rosero-Bixby, with Co-Principal Investigators Xinia Fernández (University of Costa Rica) and William H. Dow (University of California, Berkeley).

Methodology

Sample:
The sample was drawn from Costa Rican residents in the 2000 population census who were born in 1945 or before, with an over-sample of the oldest-old (ages 95 and over).

Time Method:
Longitudinal

Weight:
The variable "ponderador" contains sampling weights that must be used to obtain nationally representative estimates of population averages, percentages and so on. Analyses controlling for age, sex, urban residence, and education, such as multiple regressions, do not need to use these weights. These sampling weights were normalized in such a way that the un-weighted sampling size (N = 2,827) is reproduced with weighted estimates. Weights also replicate the structure by sex, age, urban residence, and education of the population of Costa Rica born in 1945 or before and alive at 2005. The weights range from a minimum of 0.07 for men 95 years of age and older with low education, to a maximum of 3.85 for men age 60-64, high education and rural residence. These sampling weights were meant to correct two facts: (1) The over-sampling of oldest old individuals included purposely in the sampling design to have enough statistical power to analyze advanced ages. (2) The higher no-response rates that occurred in the fieldwork among younger men, in high SES and urban settings.